NilfiskCFM  and 3508 and 3307 and and 3306 3 phase industrial vacuum cleaner downstream Class H14 Absolute filtration, 7.25m2 panel filter with the dimensions of 457mm long x 610mm wide x 150mm thick compared to SKU  which is 300mm thick.

It is generally is found in a painted box on the opposite end of the machine to the hose, such as in the second picture.

You'll also see in the latter pictures, the filter can also be used in a formation similar to SKU  where it's mounted above the motor position, like in the old photo with the lathe, apparently, in this application, the lathe is cutting Graphite.

I HAVE ONLY ONE AT THIS PRICE

At the moment standard postage within Australia, is capped at a maximum of $25, so maximise the saving on postage and buy something in related items below!